%AWang, Chengyu%AGupta, Adbhut%AMadathil, Pranav%ASingh, Siddharth%AChung, Yoon%APfeiffer, Loren%ABaldwin, Kirk%AShayegan, Mansour%BJournal Name: Proceedings of the National Academy of Sciences; Journal Volume: 120; Journal Issue: 52
%D2023%IPNAS
%JJournal Name: Proceedings of the National Academy of Sciences; Journal Volume: 120; Journal Issue: 52
%K
%MOSTI ID: 10502053
%PMedium: X
%TNext-generation even-denominator fractional quantum Hall states of interacting composite fermions
%XThe discovery of the fractional quantum Hall state (FQHS) in 1982 ushered a new era of research in many-body condensed matter physics. Among the numerous FQHSs, those observed at even-denominator Landau level filling factors are of particular interest as they may host quasiparticles obeying non-Abelian statistics and be of potential use in topological quantum computing. The even-denominator FQHSs, however, are scarce and have been observed predominantly in low-disorder two-dimensional (2D) systems when an excited electron Landau level is half filled. An example is the well-studied FQHS at filling factor$\mathit{\nu}\mathbf{=}$5/2 which is believed to be a Bardeen-Cooper-Schrieffer-type, paired state of flux-particle composite fermions (CFs). Here, we report the observation of even-denominator FQHSs at$\mathit{\nu}\mathbf{=}$3/10, 3/8, and 3/4 in the lowest Landau level of an ultrahigh-quality GaAs 2D hole system, evinced by deep minima in longitudinal resistance and developing quantized Hall plateaus. Quite remarkably, these states can be interpreted as even-denominator FQHSs of CFs, emerging from pairing of higher-order CFs when a CF Landau level, rather than an electron or a hole Landau level, is half-filled. Our results affirm enhanced interaction between CFs in a hole system with significant Landau level mixing and, more generally, the pairing of CFs as a valid mechanism for even-denominator FQHSs, and suggest the realization of FQHSs with non-Abelian anyons.

%0Journal Article